Transport vehicles with positive drives are known, for example, cog railways and in the mining industry. Positive drives have an advantage over friction drives in that the efficiency can be improved because the drive wheel in the case of a positive connection cannot slip on the drive rail. In addition, greater torques and thus greater accelerations can be transferred from the drive to the vehicle.
These drives have already been proposed for use in roller coasters, too. However, there is the problem that the rack limits the possibilities for the realization of certain routes. As roller coasters are intended to thrill users by traversing the most spectacular possible thrill elements, a complicated route with more or less steep rises (e.g. camel back), curves, twists (e.g. screw), and also combinations of these (e.g. cork screw), must be realized in many cases. However, since the racks, as well as the guide elements (rails), are not freely bendable and twistable, there is limited scope for designing the circuit.
Since the rack generally in addition to the rails is attached, for example, between a dual line of rails, it is difficult to integrate such a roller coaster into an existing landscape or environment. In the case of a dual rail track, the passengers always see the rails and the toothing and so can easily anticipate the course. This can partially reduce the thrill of the ride.
Furthermore, positive drives suffer from the fundamental problem of high wear and high noise levels. This gives rise to higher energy requirements and can detract from the quality of the ride during transport of persons.